/*
 * Copyright (c) 2016 Zibin Zheng <znbin@qq.com>
 * All rights reserved
 */

#include "multi_button.h"

#define EVENT_CB(ev)    \
    if (handle->cb[ev]) \
        handle->cb[ev]((Button*)handle)

//button handle list head.
static struct Button* head_handle = NULL;

/**
  * @brief  Initializes the button struct handle.
  * @param  handle: the button handle strcut.
  * @param  pin_level: read the HAL GPIO of the connet button level.
  * @param  active_level: pressed GPIO level.
  * @retval None
  */
void button_init(struct Button* handle, uint8_t (*pin_level)(), uint8_t active_level)
{
    memset(handle, 0, sizeof(struct Button));
    handle->event = (uint8_t)NONE_PRESS;
    handle->hal_button_Level = pin_level;
    handle->button_level = handle->hal_button_Level();
    handle->active_level = active_level;
}

/**
  * @brief  Attach the button event callback function.
  * @param  handle: the button handle strcut.
  * @param  event: trigger event type.
  * @param  cb: callback function.
  * @retval None
  */
void button_attach(struct Button* handle, PressEvent event, BtnCallback cb)
{
    handle->cb[event] = cb;
}

/**
  * @brief  Inquire the button event happen.
  * @param  handle: the button handle strcut.
  * @retval button event.
  */
PressEvent get_button_event(struct Button* handle)
{
    return (PressEvent)(handle->event);
}

/**
  * @brief  Button driver core function, driver state machine.
  * @param  handle: the button handle strcut.
  * @retval None
  */
void button_handler(struct Button* handle)
{
    uint8_t read_gpio_level = handle->hal_button_Level();

    //ticks counter working..
    if ((handle->state) > 0)
        handle->ticks++;

    /*------------button debounce handle---------------*/
    if (read_gpio_level != handle->button_level) { //not equal to prev one
        //continue read 3 times same new level change
        if (++(handle->debounce_cnt) >= DEBOUNCE_TICKS) {
            handle->button_level = read_gpio_level;
            handle->debounce_cnt = 0;
        }
    } else { //leved not change ,counter reset.
        handle->debounce_cnt = 0;
    }

    /*-----------------State machine-------------------*/
    switch (handle->state) {
    case 0:
        if (handle->button_level == handle->active_level) { //start press down
            handle->event = (uint8_t)PRESS_DOWN;
            EVENT_CB(PRESS_DOWN);
            handle->ticks = 0;
            handle->repeat = 1;
            handle->state = 1;
        } else {
            handle->event = (uint8_t)NONE_PRESS;
        }
        break;

    case 1:
        if (handle->button_level != handle->active_level) { //released press up
            handle->event = (uint8_t)PRESS_UP;
            EVENT_CB(PRESS_UP);
            handle->ticks = 0;
            handle->state = 2;

        } else if (handle->ticks > LONG_TICKS) {
            handle->event = (uint8_t)LONG_PRESS_START;
            EVENT_CB(LONG_PRESS_START);
            handle->state = 5;
        }
        break;

    case 2:
        if (handle->button_level == handle->active_level) { //press down again
            handle->event = (uint8_t)PRESS_DOWN;
            EVENT_CB(PRESS_DOWN);
            handle->repeat++;
            EVENT_CB(PRESS_REPEAT); // repeat hit
            handle->ticks = 0;
            handle->state = 3;
        } else if (handle->ticks > SHORT_TICKS) { //released timeout
            if (handle->repeat == 1) {
                handle->event = (uint8_t)SINGLE_CLICK;
                EVENT_CB(SINGLE_CLICK);
            } else if (handle->repeat == 2) {
                handle->event = (uint8_t)DOUBLE_CLICK;
                EVENT_CB(DOUBLE_CLICK); // repeat hit
            }
            handle->state = 0;
        }
        break;

    case 3:
        if (handle->button_level != handle->active_level) { //released press up
            handle->event = (uint8_t)PRESS_UP;
            EVENT_CB(PRESS_UP);
            if (handle->ticks < SHORT_TICKS) {
                handle->ticks = 0;
                handle->state = 2; //repeat press
            } else {
                handle->state = 0;
            }
        }
        break;

    case 5:
        if (handle->button_level == handle->active_level) {
            //continue hold trigger
            handle->event = (uint8_t)LONG_PRESS_HOLD;
            EVENT_CB(LONG_PRESS_HOLD);

        } else { //releasd
            handle->event = (uint8_t)PRESS_UP;
            EVENT_CB(PRESS_UP);
            handle->state = 0; //reset
        }
        break;
    }
}

/**
  * @brief  Start the button work, add the handle into work list.
  * @param  handle: target handle strcut.
  * @retval 0: succeed. -1: already exist.
  */
int button_start(struct Button* handle)
{
    struct Button* target = head_handle;
    while (target) {
        if (target == handle)
            return -1; //already exist.
        target = target->next;
    }
    handle->next = head_handle; /*在头部添加按键列表*/
    head_handle = handle;
    return 0;
}

/**
  * @brief  Stop the button work, remove the handle off work list.
  * @param  handle: target handle strcut.
  * @retval None
  */
void button_stop(struct Button* handle)
{
    struct Button** curr;
    for (curr = &head_handle; *curr;) {
        struct Button* entry = *curr;
        if (entry == handle) {
            *curr = entry->next;
            //			free(entry);
        } else
            curr = &entry->next;
    }
}

/**
  * @brief  background ticks, timer repeat invoking interval 5ms.
  * @param  None.
  * @retval None
  */
void button_ticks()
{
    struct Button* target;
    for (target = head_handle; target; target = target->next) {
        button_handler(target);
    }
}
